BAS Due Dates 2026-27: Every Australian Deadline

The next quarterly BAS deadline is 28 October 2026 (Q1, July-September), or 25 November 2026 if lodged by a registered BAS agent. Q2 (October-December) is due 28 February 2027 - which falls on a Sunday, so the effective deadline is Monday 1 March 2027, with no separate agent concession. This page lists every BAS due date for the 2026-27 financial year, including monthly deadlines, self-lodger online concessions, agent concession dates, and the penalties for late lodgement - now $364 per 28-day period overdue from 1 July 2026

The Australian Taxation Office sets different BAS lodgement and payment deadlines depending on whether you report monthly, quarterly, or annually - and depending on how you lodge. Missing these dates triggers automatic penalties and interest, and since 1 July 2025 that interest is no longer tax-deductible. Getting your dates right matters more than ever

Quarterly BAS due dates 2026-27

Most Australian small and medium businesses with GST turnover under $20 million lodge BAS quarterly. The self-lodged deadline is the 28th of the month following the end of each quarter. The one exception is Q2 (the December quarter), which has a built-in one-month extension to 28 February because of the holiday period

Important - The BAS agent concession dates only apply if your registered BAS agent has lodged your previous activity statement electronically and you are eligible under the ATO lodgement program. If your agent is lodging your first-ever activity statement, or your previous BAS was lodged on paper, you may need to meet the earlier self-lodged deadline. Check with your agent to confirm which date applies to you

If a due date falls on a weekend or public holiday, the deadline automatically extends to the next business day

Monthly BAS due dates 2026-27

Businesses with GST turnover of $20 million or more must report monthly. Some smaller businesses also elect to report monthly - usually because they are regularly in a GST credit position and want faster refunds

Monthly BAS is due on the 21st of the following month, every month. There is no agent concession for monthly BAS, with one exception (December)

The December monthly BAS is the only month where registered BAS agents get a concession - an extra month, pushing the statutory deadline from 21 January to 21 February (and because 21 February 2027 is a Sunday, the effective agent date is Monday 22 February 2027). This concession only applies to businesses with turnover up to $10 million who lodge electronically through a registered agent

Annual BAS

Businesses that are voluntarily registered for GST with annual turnover under $75,000 ($150,000 for not-for-profits) can elect to report and pay GST annually. The due date is 31 October 2027 for the 2026-27 year, or 28 February 2028 if you do not have a tax return lodgement obligation

Annual reporting suits very small businesses with straightforward GST positions. If your business is growing, quarterly reporting gives you better visibility of your GST position throughout the year and avoids a large end-of-year payment

What goes on your BAS

Your BAS covers more than just GST. Depending on your business, it can include several different tax obligations reported on a single form:

Goods and Services Tax (GST) - the difference between GST collected on sales and GST paid on purchases. This is the core obligation for most businesses

PAYG withholding - the tax you withhold from employee wages and contractor payments. Small withholders (withholding under $25,000 per year) report this quarterly on their BAS. Medium withholders ($25,000 to $1 million) report monthly

PAYG instalments - prepayments towards your own income tax liability, calculated based on your prior year tax assessment. The ATO sets either a fixed instalment amount or a rate you apply to your current income

Fuel tax credits - if your business uses fuel in machinery, heavy vehicles, or certain other applications, you claim credits through your BAS

Fringe Benefits Tax (FBT) instalments - quarterly FBT instalments for businesses that provide fringe benefits to employees. What counts as a fringe benefit and how it is calculated is a question for your accountant

Wine equalisation tax and luxury car tax - reported on BAS by businesses in those sectors

Getting any of these wrong affects more than just your BAS - it flows through to your annual tax position. This is why accurate bookkeeping throughout the quarter matters far more than a last-minute scramble before the deadline

What happens if you lodge late

The ATO has two separate consequences for late BAS: a failure to lodge penalty and interest on any unpaid amount. Both apply independently - you can be hit with both at the same time. We see both triggered most often when a business changes bookkeepers mid-quarter and nobody picks up where the previous person left off

Failure to lodge (FTL) penalty

If you miss the BAS deadline, the ATO can impose a failure to lodge penalty. The penalty is calculated in penalty units - one unit for every 28-day period (or part thereof) that the BAS is overdue, up to a maximum of five penalty units

For infringements on or after 1 July 2026, one penalty unit is worth $364 (up from $330). The base penalty is multiplied based on your business size:

These penalties apply per late lodgement. If you are late on two quarters, you face two separate penalties. A small business that misses all four quarterly BAS lodgements in a year could face several thousand dollars in penalties - even if the BAS results in a nil or refund outcome

The ATO generally warns you before applying FTL penalties and gives you a chance to lodge. If you use a registered tax or BAS agent, safe harbour provisions may apply in some circumstances, which can protect you from an FTL penalty where you gave your agent everything they needed on time. But if there is a pattern of late lodgement, penalties are increasingly likely to be applied automatically

General Interest Charge (GIC)

If you owe money on your BAS and do not pay by the due date, the ATO charges General Interest Charge on the unpaid amount. GIC is calculated daily on a compounding basis

The GIC rate for the July-September 2026 quarter is 11.43% per annum. The rate is reviewed quarterly and is tied to the Reserve Bank 90-day bank bill rate plus a 7% uplift, so check the current quarter before relying on a figure

Critical change from 1 July 2025 - GIC is no longer tax-deductible. Previously, businesses could claim a deduction for GIC paid, which reduced the after-tax cost. Under the current rules, the full amount comes out of after-tax dollars. A $10,000 GIC bill now costs the full $10,000. This makes paying your BAS on time significantly more important than it was even two years ago

How to stay on top of BAS deadlines

The businesses that never stress about BAS deadlines have one thing in common: their bookkeeping is current throughout the quarter, not just at the end of it. Across our client base, the ones who reconcile weekly lodge BAS days after quarter end. The ones who batch it all in the final week are the ones chasing receipts at midnight. Here is what that looks like in practice

Reconcile weekly, not quarterly. If you are using Xero, bank feeds update automatically. Set aside 30 minutes each week to code transactions and reconcile. When the quarter ends, your BAS preparation is a review exercise, not a data entry marathon

Separate your GST and PAYG withholding funds. Open a dedicated savings account and transfer your estimated GST and PAYG amounts after each pay run or invoicing cycle. When the BAS payment is due, the money is already set aside. This eliminates the cashflow shock of a large quarterly payment

Use Xero Activity Statements. Xero generates your BAS directly from your coded transactions. If your bookkeeping is current, Xero can prepare a draft BAS in minutes. Your BAS agent can then review, adjust, and lodge electronically - which also qualifies you for the agent concession deadlines

Lodge early when you are in a refund position. If your business regularly pays more GST on purchases than it collects on sales, you are in a net refund position. Lodge as early as possible after the quarter ends to get that money back into your business faster. There is no benefit to waiting until the deadline when the ATO owes you money

Set calendar reminders four weeks before each deadline. The reminder is not for lodging - it is for your bookkeeper or BAS agent to start preparing. Giving your agent four weeks means they can review your records, raise any queries, and lodge with time to spare. Last-minute lodgements are where errors happen

When to use a registered BAS agent

A registered BAS agent does more than give you extra time to lodge. They take responsibility for the accuracy and compliance of your BAS, and where you have given them what they need on time, the ATO safe harbour provisions can protect you from certain penalties

Using a BAS agent makes particular sense if your business has employees (PAYG withholding adds complexity), if you claim fuel tax credits, if you have a mix of GST-free and taxable supplies, or if you simply do not want to think about BAS compliance at all

At Digit, BAS preparation and lodgement is part of our core bookkeeping service. Your books are maintained continuously through the quarter, so when the deadline approaches, your BAS is already prepared. No last-minute scrambles, no late lodgements, no penalties

Key dates calendar - 2026-27 at a glance

Pin this to your wall or save it to your phone. Every quarterly BAS deadline for the financial year in one list:

Monthly BAS lodgers: your deadline is the 21st of the following month, every month, moving to the next business day when the 21st is a weekend or public holiday. The only concession is the December statement noted above

BAS is one deadline among several. Our compliance guides cover the rest of the calendar, and because PAYG withholding flows straight from payroll, the people and payroll guides are worth a look if wages are part of your BAS

All dates and penalty information in this article are sourced from the Australian Taxation Office, current as at July 2026. We update this page each financial year